Neon signs are well known in the art. Such signs have been particularly popular due to the way their intense coloration and brightness attracts attention, and therefor customers. Artists have used neon as an artistic medium as well.
Neon signage, however, is expensive. Most neon signs may require painstaking hand craftsmanship, involving careful glass bending and blowing of individual shapes, and charging and testing of individual tubes. In addition, different colors require different gases within each tube, making multi-colored signs expensive.
Neon signs are also difficult and expensive to maintain, and break easily. Roadway signs are easy targets for vandals and the like. Once damaged, a neon sign owner must obtain the services of a neon sign craftsman to make and install new tubes. Old tubes, even if not damages, may start to flicker and buzz, giving the sign a seedy and disreputable appearance.
As a result, other types of illuminated signage have become popular. Back-lit signs, using fluorescent tubes encased within a translucent (e.g., white) housing have been popular. However, such signs have been criticized as being aesthetically displeasing. In addition, such signs may weather with age,a nd are also subject to brittle breakage.
For indoor use, a form of faux neon has become popular using edge lit plexiglass.TM. sheets, lit with ultraviolet or "black" light. Sign elements may be painted into grooved portions of the plexiglas sheet using fluorescent paints or the like. Grooving and painting the plexiglas may be rather expensive, however, and such signs have generally found acceptance only for indoor use. In addition, black light tubes may be as much as 5 to 10 times as expensive as conventional fluorescent lamps.
Colored tubes for colorizing fluorescent or neon tubes are also known in the art. Such colored sleeves may typically slide over a standard (e.g., 48 inch) fluorescent tube to provide a colored light effect. Clear tubes are also known for protecting fluorescent tubes from breakage.
Murai, U.S. Pat. No. 5,416,674, issued May 16, 1995, discloses a black light display device. An ultraviolet radiation lamp contains a transparent tube that coaxially receives the ultraviolet lamp and which is rotatable about an axial center line. Images are painted or printed on either the outer surface of the ultraviolet lamp, or on a substantially transparent film placed over the surface of the transparent tube, with a fluorescent ink which emits light when ultraviolet light is radiated upon it. The lighted images are projected onto a concave reflective surface, which may also have images painted on it with a fluorescent ink.
Jung U.S. Pat. No. 4,864,475, issued Sep. 5, 1989, discloses a rainbow light box. A colorful illuminated sign construction utilizes plurality of fluorescent lamp covered by colored transparent plastic thin wall tubing which is tightly enclosed by a diffusion panel sleeve so that neighboring colors may be diffused by the diffusing panel. It is said to form colorful stripes to attract attention. The fluorescent lamps and color sleeves are held by openings installed on side frame posts at both ends of fluorescent lamp. The side frame posts are connected to horizontal conduit and connecting bar which forms a structural frame of sign.
Palumbo, U.S. Pat. No. 4,727,459, issued Feb. 23, 1988, discloses a technique for surrounding a neon tube with a clear or tinted plastic tube. Palumbo teaches that the use of the clear or tinted plastic tube enhances the lighting effect of the neon tube.